Just ordered 2.5" stainless down pipe with CAT. Can't wait to see how this adds to the GMPP exhaust note and performance.

 

I've helped installed and heard and felt the addition of one of these. Very nice unit. You'll enjoy!

 

I got the ZZP downpipe installed. It sounds great with GMPP exhaust, and more punch to. CEL came on two days later. I'm assuming this is normal, car runs fine so I'm not too concerned.

 

Normal Cat code. You'll need to get it tuned out if you want to pass emissions (depending on your laws)

 

If you can't afford a tune at the moment, look into the spark plug non-fouler trick. When I was getting my ZZP downpipe, I found a lot of people with a variety of drive trains and high flow cats have used that trick as the cheap way out.

It basically spaces the O2 sensor out of the exhaust stream.

 

Thanks for the advice. I'm going to give it a try.